Answer: conversion of ice to steam
Explanation: Endothermic process is one in which energy is absorbed by the system.
Conversion of ice to steam is change of solid phase to gaseous phase, thus energy is required to break the strong inter molecular forces of attraction in solids to convert it into gaseous phase.
Conversion of steam to ice, conversion of steam to water and conversion of water to ice releases energy and are examples of exothermic processes.
Answer: Options (a) and (d) are the correct answer.
Explanation:
A catalyst is the substance which helps in increasing the rate of reaction.
Activation energy is the minimum amount of energy required by reactants to start the reaction. On addition of catalyst, the path of reaction changes because the energy barrier gap reduces and hence, the activation energy also decreases.
In the absence of catalyst, we need to increase the temperature so that reaction can occur quickly.
Whereas on addition of catalyst, there is no need to increase the temperature as the catalyst itself is sufficient to increase the rate of reaction. As a result, temperature should be lowered when there is addition of catalyst in the reaction.
Thus, we can conclude that catalysts can save money by essentially lowering the activation energy and temperature required.
Answer:
See explanation
Explanation:
Crystals can be made from methanol by recrystallizing the plant extract from methanol.
The methanol/water system is heated rapidly using a hot plate and the plant extract dissolves in the heating solution until a clear solution is obtained.
The solution is now cooled rapidly. The interior of the flask used for the re crystallization may even by scratched to assist the quick formation of crystals. Large crystals of plant compounds may be obtained using this method. This process should be carried out in a fume hood because of the toxicity of methanol.
Answer:
100,000 N
Explanation:
Force, F = mass, m × acceleration, a
⇒F = ma
m= 20, 000kg
a = 5m/s²
∴ F = 5 × 20,000 = 100,000N
